如何在R中将数据帧转换为列表? [英] How to transform a data frame into a list in r?

问题描述

能请你帮我吗?

我想根据R数据帧中包含的信息列出一个列表.我找到了解决方案，但这不是一般的解决方法.

I want to make a list based on information contained in an R data frame. I found a solution, but it is not general.

例如，让我们从以下数据框开始:

For instance, let's start with this data frame:

df <- data.frame(vertices = paste(letters[1:20]), modules = rep(1:4, 5))

我想使用 df $ modules 将数据框转换为列表.列表中的项目应包含来自 df $ vertices 的数据.所以我找到了解决方案:

I want to use df$modules to turn the data frame into a list. The items of the list should contain data from df$vertices. So I found this solution:

list1 <- split(df, df$modules)

list2 <- vector(mode = "list", length = length(unique(df$modules)))
list2[[1]] <- as.vector(list1[[1]]$vertices)
list2[[2]] <- as.vector(list1[[2]]$vertices)
list2[[3]] <- as.vector(list1[[3]]$vertices)
list2[[4]] <- as.vector(list1[[4]]$vertices)

如您所见，它可以工作，但不是通用的，因为您需要在代码的末尾手动添加很多行作为 length(unique(df $ modules)).

As you can see, it works, but it's not general, because you need to manually add so many lines to the code's end as length(unique(df$modules)).

我也尝试了while循环，但是没有用:

I've also tried a while loop, but it didn't work:

i <- 1

while (i == length(list2)) {
    list2[[i]] <- as.vector(list1[[i]]$vertices)
    list2
}

是否有解决此问题的一般方法?谢谢！

Is there a general solution to this problem? Thank you!

推荐答案

您快到了:

split(df$vertices, df$modules)

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